It is known to provide separable end members at one end of a slide fastener stringer, one of these members constituting an insertion member while the other member constitutes a reception member adapted to receive the insertion member when the latter is fed through a corresponding channel of a slider disposed at the reception member.
The slider, which can have a Y-shaped channel configuration, is displaceable along the stringer to interconnect the rows of coupling elements or disconnect the same. The coupling elements may be heads which are spaced apart to receive the heads of the opposing row between them, the heads being part of a continuous coupling coil or meander, or being discrete coupling heads mounted, e.g. by molding, upon an edge of a respective support tape. One end member, the respective row of coupling elements or heads, and the support tape carrying same constitute a respective stringer half. Two such stringer halves and an associated slider constitute a slide fastener stringer in accordance with the present invention.
The straight leg of the channel of the slider is generally dimensioned so that its width is less than twice the lengths of the coupling elements so that the latter are drawn together and forced between the coupling elements of the opposing row as the two rows of coupling elements pass through the convergent legs of the channel to the aforementioned straight portion thereof.
The slider may also have flanks which receive the end stop members between them or at least portions of these end stop members.
In conventional slide fasterner stringers of the aforedescribed type, the insertion member forms a so-called plug while the reception member is constituted as a socket receiving the plug. The end members, upon separation, permit the slider to remain upon the reception member or socket after the insertion member or plug is withdrawn to permit the normally juxtaposed edges of the stringer to be spread apart. Typical use of such a slide fastener stringer is in a jacket or garment which is to be fully opened.
In the closed condition of the slide fastener, however, the plug remains locked in the socket and the slider is in the position remote from these end members which also serve to prevent the slider from being withdrawn fully from the stringer. In this position, the coupling elements of the two rows between the slider and the end members are interfitted or interdigitated with the heads of the coupling elements of one row being received between the heads of the coupling elements of the other row and vice versa.
There are, however, also slide fastener stringers known in which the plug-and-socket relationship is not used and which nevertheless permit separation of the end members. Reference is made in this connection to the open German application (Offenlegungsschrift) DT-OS No. 25 10 098.
In this case, the end members mutually engage without either being formed with a box-like socket or housing and without the other being constituted as a plug which is wholly enclosed within such a housing-shaped socket. In this arrangement, the insertion member engages the reception member and the two members are formed, transversely to the slide fastener plane, with an offset step which permits form-fitting engagement and nevetheless precludes transverse dislocation of the interengaged end stop members.
In this construction, however, the insertion member as well as the reception member have straight flanks which confront the flanks of the slider between which the two members are received.
As a consequence, when the slider is not fully in a position enclosing the reception member, the insertion member cannot be introduced with ease and hence there is encountered difficulty with introduction of the insertion member in the reception member of engagement of the two upon closing of the slide fastener.
Because of these difficulties, the manipulation of the end members and the slide during closing and during disengagement (separation of the stringer halves) is difficult. Finally, this construction does not readily permit automatic drawing of the slider onto the stringer, i.e. automatic or trouble-free mounting of the slider in assembly of the stringer.